With development of mobile communications technologies, large quantities of radio base stations are distributed in places requiring mobile communications coverage, such as cities and rural regions. A typical radio base station mainly includes a baseband unit (BBU), a remote radio unit (RRU), a power supply system, a backup power supply system, and a direct current power distributor. A function of the power supply system is to convert an input alternating current into a direct current, and supply a direct current to the BBU (mainly including a BBU service unit) and the RRU (mainly including an RRU service unit) by using the direct current power distributor. A function of the backup power supply system is to supply a direct current to the BBU and the RRU by using the direct current power distributor in a case of an alternating current power outage. In practice, the BBU, the power supply system, the backup power supply system, and the direct current power distributor are generally installed at the tower bottom for ease of manual maintenance, but the RRU is generally installed at the tower top close to an antenna to reduce a feeder loss. The BBU exchanges service data with the RRU by using a common public radio interface (CPRI), and the BBU can perform control (such as automatic reset, fault query, diagnosis, and fault recovery) on the RRU (mainly the RRU service unit) by using the CPRI.
In practice, it is found that the BBU controls the RRU depending on the unique communications interface CPRI. When the CPRI is abnormal, the BBU loses the capability of controlling the RRU.